Such electronic devices, like, for example, a monitor connected to a computer, can often also assume several energy-saving states. In the first energy-saving state, as a rule, as many loads are turned off in the electronic device that a quick change into the operating state is possible, while for assuming the energy-saving state with the maximum energy savings, the loads in the electronic device are turned off so far that a return to the operating state is only possible, for example, by a user input, in an example for a system consisting of a monitor and computer, by an input of the user on the computer.
In monitors, there are several classifications for energy-saving states, for example, the VESA standard, wherein the energy-saving states are defined with VESA ON=operating state, VESA SUSPEND=first energy-saving state, VESA STANDBY=second energy-saving state, and VESA OFF=third energy-saving state.
Other standards, like, for example, the DVI standard (Digital Video Interface) have similar definitions, but the energy-saving states are named differently.
All electronic devices that can assume an energy-saving state and are provided with a power supply have in common, however, that even in the maximum energy-saving state, the evaluation unit that can initiate a change from the energy-saving state back into the operating state must still be powered via the power supply. This means that in solutions known up to now, the power supply is in continuous operation during the energy-saving state.
This causes a power consumption of 1-2 W even in the maximum energy-saving state, for example, in a monitor.